Instantaneous calender device with spring and tappet mounted on rotary shifter

ABSTRACT

An instantaneous calendar device is disclosed. 
     The instantaneous calendar device comprises a stationary part, for example, a bridge, a date ring, a day disk, a rotary shifter, and an actuator. The rotary shifter operates the date ring and the day disk. The actuator is composed of a spring, a tappet, and a calendar wheel coaxial with a cam. The cam of the actuator is rigidly secured to the stationary part of the device, whereas the tappet and the spring are mounted on the rotary shifter.

FIELD OF THE INVENTION

The invention relates to timepieces, more specifically to small wristwatches, and has particular reference to instantaneous calendar devicesused therein.

DESCRIPTION OF THE PRIOR ART

Well known in the art are instantaneous timepiece calendar devicescomprising an actuator composed of a spring, a tappet, and a calendarwheel mounted coaxially with a cam, a rotary shifter operating a datering and a day disk, and stops. When the calendar wheel rotates, itsspoke engages a pin provided on the cam, which is rotatably mounted onthe axle of the calendar wheel, whereby the cam is rotated. The cam isconnected with the rotary shifter which has projections arranged toengage the teeth of the date ring and of the day disk. The tappet ismounted on the watch plate. One of the tappet arms rides on the cam,thereby winding the spring which is also mounted on the plate. Theactuator accumulates energy required for rapidly shifting the date ringand the day disk once in 24 hours. The shifting of the date ring and theday disk is effected by the shifter when the tappet leaves the cam peak.

However, due to the above described arrangement of the tappet, springand cam in the calendar device, the actuator occupies a considerablearea of the watch plate. This disadvantage is a hindrance to employingsuch a calendar device in small wrist timepieces, for example, in lady'swatches.

Also known in the art is an instantaneous timepiece calendar devicewherein the tappet is made as a cut spring one end of which is rigidlysecured to the watch plate, whereas the other end rides on the sidesurface of the cam. The day disk is shifted by the cam pin whichoperates the disk through an intermediate star wheel.

With this constructional arrangement, the actuator suffers from thedisadvantage that it occupies a considerable area and adds to frictionallosses of energy due to the use of the intermediate star wheel fortransmitting rotation from the cam to the day disk. A furtherdisadvantage is that the device under consideration is poorly suited formanufacture since the tappet made in the form of a cut springnecessitates extra time and labor for adjusting the calendar mechanismand excludes the possibility of using a spring band, which possesseshigher stability of force characteristics and is conventionally employedin actuators.

Referring to USSR Inventor's Certificate 245669, class G 04B19/24published in 1969, the instantaneous calendar device disclosed thereincomprises a cam-type actuator, two shifting elements, one for a datering and the other for a day disk, and stops.

The shifting elements are each made in the form of two pins located onthe face of a wheel and passing through a slot in a coaxial intermediatewheel which meshes with one of the watch train wheels.

This calendar device suffers from the disadvantage that, due to thedesign of the shifting mechanism, additional adjustments are required inassembling the device.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an instantaneouscalendar device with the actuator thereof designed so as to enabledecreasing the dimensions of the calendar device and thereby tofacilitate incorporation thereof in small lady's wrist watches.

The invention provides an instantaneous calendar device comprising anactuator composed of a spring, a tappet and a calendar wheel coaxialwith a cam, a rotary shifter operating a date ring and a day disk, andstops.

According to the invention, the actuator cam is rigidly secured to thestationary part of the calendar device, whereas the tappet and thespring are mounted on the rotary shifter.

Owing to the design wherein the cam is rigidly secured to the stationarypart, whereas the tappet and the spring are mounted on the rotaryshifter, the major elements of the device are interconnected in a novelmanner so that they occupy substantially less area than in the devicesof the prior art, said area being equal to the projection of thecalendar wheel onto the watch plate, and can be arranged withoutincreasing the height of the calendar mechanism, due to which thecalendar device of the present invention can be incorporated in lady'swrist watches within the restrictions set by their size.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be more particularly described by way of examplewith reference to the accompanying drawings, wherein:

FIG. 1 is a fragmentary diagrammatic top view of the calendar deviceaccording to the invention; and

FIG. 2 is a sectional view on the line II--II of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The instantaneous calendar device comprises an actuator 1 (FIG. 1), arotary shifter 2, a date ring 3, a day disk 4 (FIG. 2), a stop 5 (FIG.1), and stationary parts of the calendar device, for example, a plate(not shown) and a bridge 6 (FIG. 2).

The actuator 2 (FIG. 1) is composed of a spring 7, a tappet 8 made inthe form of an L-shaped double-arm lever, a calendar wheel 9, and a cam10.

Installed in the bridge 6 (FIG. 2) is an axle 11 on which is freelymounted the calendar wheel 9 meshing with an hour wheel 12. The body ofthe calendar wheel 9 has an opening 13 which receives a pin 14 (FIG. 1)installed in the shifter 2. The shifter 2 has projections 15 and 16designed to engage once in 24 hours with the date ring 3 and the starwheel 17 of the day disk 4, which star wheel is fashioned as a Maltesecross and is installed coaxially with the hour wheel 12.

The tappet 8 and the spring 7 are mounted on the rotary shifter 2, thespring 7 being installed in an arc-shaped recess 18 formed in the bodyof the shifter 2. One end of the spring 7 fits into the end of therecess 18, the other end of the spring 7 is articulated to one of thearms of the tappet 8.

The tappet 8 is situated in the opening 13 provided in the calendarwheel 9 and is freely mounted on an axle 19 secured in the body of theshifter 2. The free arm of the tappet 8 has a projection 20 (FIG. 2)interacting with the cam 10 which is mounted coaxially with the calendarwheel 9 and is rigidly secured by means of a pin 21 to the stationarypart of the calendar device, for example, the bridge 6 or the plate (notshown).

The stop 5 of the date ring 3 is installed on the stationary part of thecalendar device. The function of the stop for the star wheel 17 of theday disk 4 is fulfilled by the outer surface of the shifter 2 whichengages with the teeth of the star wheel 17.

Apart from the aforesaid parts constituting the calendar device, use ismade of conventional interacting parts designed to provide for thefunctioning of the calendar device both in automatic operation and inmanual correction.

The calendar device operates as follows;

The hour wheel 12 rotates the calendar wheel 9 which, in turn, rotatesthe shifter 2 by means of the pin 14. The slow rotation of the shifter 2is transmitted to the tappet 8 mounted on the axle 19.

The projection 20 of the tappet 8 is held against the lobe of the cam 10and rides thereon, loading the spring 7 which thereby accumulatesenergy.

When the projection 20 of the tappet 8 reaches the peak of the cam 10and the spring 7 is compressed to a maximum, the abrupt slope of the cam10 permits the spring 7 to sharply turn the shifter 2. Now theprojection 15 of the shifter 2 engages the groove in the date ring 3 andturns the date ring by one tooth. At the same time the pin 22 secured inthe projection 16 of the shifter 2 enters the nearest groove in the starwheel 17 of the day disk 4, turning it through 1/7th of a revolution.

Thereafter the cycle is repeated.

FIELD OF APPLICATION

The instantaneous calendar device is to be used in small wrist watches.

What is claimed is:
 1. An improved instantaneous calendar devicecomprising a date ring; a day disk with a star wheel; a rotary shifterwith pins interacting with said date ring and said star wheel of saidday disk to rotate said date ring and said day disk at appropriateintervals; stops retaining said date ring and said star wheel of saidday disk in position after being rotated by said pins of said rotaryshifter; and an actuator including a spring, a tappet, a calendar wheeland a cam having an abrupt slope, said rotary shifter being connected tosaid calendar wheel for rotation by said calendar wheel, said spring andsaid tappet being mounted on said rotary shifter and said cam beingmounted on a stationary portion of said calendar device, and means forcoiling said spring as said rotary shifter rotates and said spring beinguncoiled when said tappet contacts the abrupt slope of said cam to causesharp rotation of the rotary shifter and interaction of the pins of therotary shifter with the date ring and the star wheel of the day disk.